Cushions to protect against mechanical injury, controls temperture, permits symmetrical growth of the fetus, and allows the fetus freedom to move

What are functions of the placenta?

Fetal respiration, nutrition, and excretion of wastes

Describe the appearance of the placenta.

Maternal side is red and fleshlike. Fetal side is grey and shiny

Whati s the difference between the embryonic and fetal stages of development?

Embryonic stage starts on day 15 and ends at the end of the 8th week. During this time tissues differentiate into organs and the main external features develop. The developing embryo is most susceptible to tetragens during this time b/c of the development taking place.

The fetal stage begins with the 9th week and ends with birth. Development in the refining of structure and perfecting of function.

What is the chorion?

the first and outer most membrane. This thick membrane develops fromt he trophoblast and has many finger like projections called chorionic villi on its surface.

What is amnion?

The second membrane to originate during the early stages of embryonic development. It is a thin protective layer that contains amniotic fluid.

Fetal development at 4 weeks

heart begins to beat

Fetal development at 8 weeks

organs are formed, clearly resembles a human, long bones are beginning to form and this marks the end of the embryonic period

When can the fetal heart rate be ascertained?

between 8-12 weeks

Fetal development at 12 weeks

face is well formed, reflexive movement of the lips, tooth buds appear, fetus can curl the fingers to make a fist

Fetal development at 16 weeks

sex can be visualized and the fetus looks like a baby

Fetal development at 20 weeks

Lanugo covers the body; devlops a regular schedule of sleeping, sucking, and kicking; muscles are developed and the mother feels fetal movement. FHR is audible through fetoscope.

Fetal development 24 weeks

reflex hand grip and a startle reflex. The body is covered with vernix caseosa.

Fetal development at 28 weeks

the eyelids open and close under neural control, respiratory and circulatory systems have developed and surfectant is formed (stuff in the fetus's lungs to keep aveloli open)

How many ml in 24 hours does the fetus swallow and excrete?

400 ml/24hrs

Differentiate signs of pregnancy

Subjective (Presumptive): the symptoms the woman experiences and reports that may have causes other than pregnancy.

Objective (Probable): signs perceived by the examiner that also may have causes other than pregnancy

Diagnostic (Positive): signs perceived by the examiner that can be caused only by pregancy.

List some subjective (presumptive) signs of pregnancy.

Amenorrhea, N&V, urinary frequency, breast tenderness, and quickening

List some objective (probable) signs of pregnancy.

Changes in pelvic organs, enlargement of abd, braxton hick contractions, uterine souffle, changes in the pigmentation of the skin, the fetal outline on palpation, pregnancy test.

What are changes seen in the pelvic organs of a pregnant person?

Goodell's sign- softening of the cervix

Chadwicks sign- a bluish, purple, or deep red discoloration of the mucus membranes of the cervix, vagina, and vulva

Hegar's sign- softening of the isthmus of the uterus, between the cervix and body of the uterus.

McDonald's sign- an ease in flexing the body of the uterus against the cervix.

Human Chorionic Conadotropin (hCG)

stiumulates progesterone and estrogen production to maintain pregnancy until the placenta is developed. Hormone detected by home pregnancy tests.

Human Placental Lactogen (hPL)

an antagonist of insulin; it increases the amount of circulating free fatty acids for maternal metaboic needs and decreased maternal metabolism of glucose to favor fetal growth.

Estrogen

secreted by the corpus luteum, it is primarily produced by the placenta as early as the 7th week. It stimulates uterine development to provide a suitable environment for the fetus. It aslo helps develop the ductal system of the breasts in preparation for lactation.

Abnormal color may indicate porphyria, hemoglobinuria, or bilirubinemia. Alkaline urine may indicate metabolic alkalemia, Proteus infection, or an old specimen.

Normal ranges for Rubella titer (HAI)

1:10 indicates a woman is immune

if HAI is <1:10 immunization will be given on postpartum or within 6 weeks after childbirth; Instruct women whose titers are >1:10 to avoid child who have rubella

What is the most common method of determining the EDB? Explain how to apply it.

Nagele's rule

To use this method, one begins with the first day of the last menstrual period, subtracts 3 months,and adds 7 days

What is McDonald's method?

a centimeter tape is used to measure the distance abdominally from the top of the symphysis pubis to the top of the uterine fundus.

Fundal ht in cm correlates will with weeks of gestation between 22 to 24 -34 weeks.

What may indicate intrauterine growth restriction (IUGR)?

a lag in progression of measurements of fundal ht from month to month and week to week. A sudden increase in fundal ht may indicate twins or hydramnios.

Methods used to assess fetal development.

Quickening, doppler devices to assess fetal heartbeat, ultrasound is used to detect a gestational sac, fetal heart activity, and fetal breathing movement. US can also be used to make crown to rump (c-r) measurements to assess fetal age.

What is Biparietal diameter?

measurements of the fetal head can be made by approximately 12-13 weeks are are most accurate between 20-30 weeks.

How often should subsequant antepartal visits be made?

Every 4 weeks for the first 28 weeks

Every 2 weeks until 36 weeks

Every week after 36 weeks until childbirth

What are danger signs in pregnancy and the possible causes of these signs?

Increased production of progesterone, decreasing GI motility, and increasing relaxation of cardiac cphincter, displacement of stomach by enlarging uterus, thus regurgitation of acidic gastric contents into the esophagus

Abnormal color may indicate porphyria, hemoglobinuria, or bilirubinemia. Alkaline urine may indicate metabolic alkalemia, Proteus infection, or an old specimen.

Normal ranges for Rubella titer (HAI)

1:10 indicates a woman is immune

if HAI is <1:10 immunization will be given on postpartum or within 6 weeks after childbirth; Instruct women whose titers are >1:10 to avoid child who have rubella

What is the most common method of determining the EDB? Explain how to apply it.

Nagele's rule

To use this method, one begins with the first day of the last menstrual period, subtracts 3 months,and adds 7 days

What is McDonald's method?

a centimeter tape is used to measure the distance abdominally from the top of the symphysis pubis to the top of the uterine fundus.

Fundal ht in cm correlates will with weeks of gestation between 22 to 24 -34 weeks.

What may indicate intrauterine growth restriction (IUGR)?

a lag in progression of measurements of fundal ht from month to month and week to week. A sudden increase in fundal ht may indicate twins or hydramnios.

Methods used to assess fetal development.

Quickening, doppler devices to assess fetal heartbeat, ultrasound is used to detect a gestational sac, fetal heart activity, and fetal breathing movement. US can also be used to make crown to rump (c-r) measurements to assess fetal age.

What is Biparietal diameter?

measurements of the fetal head can be made by approximately 12-13 weeks are are most accurate between 20-30 weeks.

How often should subsequant antepartal visits be made?

Every 4 weeks for the first 28 weeks

Every 2 weeks until 36 weeks

Every week after 36 weeks until childbirth

What are danger signs in pregnancy and the possible causes of these signs?

Category B- animal studies show no risk, but there are no contolled studies in women, or animal studies indicate a risk, but controlled human studies fail to demonstrate a risk (penicillins).

Category C- Either no adequate animal or human testings are avaliable or animal studies show teratogenic effects, but no controlled studies in women are avaliable. (Epinephrine, betablockers, and zidovudine{drug used to decrease perinatal transmission of HIV}).

Category D- evidence of human fetal risk exists, bu the benefit of the drung in certain situations are thought to outweight the risks (tetracycline, vincristine, lithium, and hydrochlorothiazide.

A gain of 3.5-5 lbs during the first trimester, followed by a gain of about 1 lb per week during the second and third trimesters. A normal wt women who is expecting twins is advised to gain about 1.5 lbs per week during the second and third trimesters of her pregnancy.

What is the recommended increase of calories during pregnancy?

No increase during the first trimester but an increase of 300 kcal/day during the second and third trimesters

What is the purpose of carbohydrates during pregnancy?

Carbs provide the body’s primary source of energy as well as the fiber necessary for proper bowel functioning. Carbohydrate intake promotes wt gain and growth of the fetus, placenta, and other maternal tissues.

an endocrine d/o of carbohydrate metabolism, results from inadequate production or use of insulin. Insulin produced by the B-cells of the islets of Langerhans in the pancreas, lowers bolld glucose levels by enabling glucose to move fromt he blood into muscle and adipose tissue cells.

Effects of normal pregnancy on carbohydrate metabolism

Insulin needs often decrease during 1st trimester and increase during 2nd and 3rd trimesters.

The rise in serum levels of estrogen, progesterone, and other hormones stimulates increased insulin production by the maternal pancreas and increased tissue response to insulin. An anabolic (building up) state exists during the first half of pregnancy, with storage of glycogen in the liver and other tissues.

The second half of pregnancy causes an increased resistance to insulin and decreased glucose tolerance. This decrease effectivness of insulin results in a catabolic (destructive) state during fasting periods. Because increasing amounts of circulating maternal glucose and amino acids are diverted to the fetus, maternal fat is metabolized much more readily. As a result of this lipolysis, ketones may be present in the urine.

What are 4 cardinal signs and symptoms of diabetes mellitus?

polyuria, polydipsia, polyphagia, and weight loss.

What causes polyuria in DM?

frequent urination results because water is not reabsorbed by the renal tubules due to the osmotic activity of glucose.

What causes polydipsia in DM?

Excessive thirst is a result of dehydration from polyuria.

What causes polyphagia in DM?

Excessive hunger is caused by tissue loss and a state of starvation, which results from the inability of the cells to use the blood glucose.

What causes weight loss in DM?

The use of fat and muscle tissue for energy.

What is gestational diabetes mellitus (GDM)?

any degree of glucsoe intolerance that has its onset or is first diagnosed during pregnancy.

Who is at the most risk to have GDM?

women who are markedly obese, have a prior history of GDM, have glycosuria, increased maternal age, or have a strong family hx of diabetes.

Maternal risks related to DM

Hydramnios, or an increased volume of amniotic fluid is a result of excessive fetal urination because of fetal hyperglycemia.

Preeclampsia-eclampsia occurs more often in DM pregnancies due to vascular changes.

Hyperglycemia can lead to ketoacidosis. decreased gastric motility and the contrainsulin effect of hPL can predispose a women to ketoacidosis.

*Macrosomia- large for gestational age (LGA). If born vaginally, the macrosomic infant is at increased risk for shoulder dystocia and traumatic birth injuries.

*Hypoglycemia- after the umbilical cord is severed the maternal blood glucose supply is eliminated. However, continued islet cell hyperacivity leads to excessive insulin levels and depleted blood glucose in 2-4 hours.

*IUGR- infants of mother with advanced diabetes (vascular involvement) may be small due to decreased efficiency of placental perfusion.

*Respiratory distress syndrome- results from inhibition, by high levels of fetal insulin, of some fetal enzymes necessary for surfactant production.

*Polycythemia- excessive number of RBC is due to the diminished ability of glycosylated hemoglobin in the mother's blood to release o2.

*Hyperbiliruninemia- a resuld of the inability of immature liver enzymes to metabolize the increased bilirubin resulting from polycythemia.

What is sacral agenesis?

appears almost exclusively in infants of diabetic mothers.

The sacrum and lumbar spine fail to develop and the lower extremities develop incompletely.

When is GDM diagnosed?

After a failed 1 hour GTT and if 2 or more of the following values are equaled or exceeded in a 3 hour GTT:

Fasting 95 mg/dL
1 hour 180 mg/ dL
2 hour 155 mg/dL
3 hour 140 mg/dL

What are some ways to manage DM antepartal?

*Increase calorie intake by 300 kcal/day taken in three meals and three snacks. The bedtime snack is most important and should contain both protein and carbs.

*Self monitoring of Blood Glucose (SMBG) should be done 4-6 times a day.

*Insulin injections- oral hypoglycemics are never used in pregnancy b/c they cross the placenta, may be teratogenic, and stimulate fetal insulin production.

Following birth (first 15 months), infants often have a positive antibody titer, which reflects the transfer of maternal antibodies and does not indicate HIV infection.

Medication therapy for HIV/AIDS during pregnancy.

Combination antiretroviral (ARV) therapy supresses viral replicatoin, helps perserve immune function, and reduces the development of resistance. Zidovudine (ZDV) is the best known of the nucleoside analogs b/c it is the medication that was so effective in reducing perinatal transmission during early clinical trials, and indications are that it is relatively safe during pregnancy.

If diagnosed with HIV/AIDS after conception, when will the medical regimen begin?

Because the fetus is most susceptible to teratogenic effects during the first trimester, ARV therapy may be delayed until after 12 weeks gestation.

What can be done to reduce the risk of perinatal transmission of HIV/AIDS?

All pregnant women with HIV should be offered the three-part ZDV prophylaxis regimen after the first trimester. This regimen includes 1) oral ZDV daily, 2) IV ZDV during labor and until birth, and 3) oral ZDV for the infant starting 8-12 hours after birth and continuing for 6 weeks.

What type of screening is done on an HIV positve pregnant woman in addition to routine screenings?

The woman infected with HIV should be evaluated and treated for other sexually transmitted diseases and for conditions occuring more commonly in women with HIV, such as TB, cytomegalovirus, toxoplasmosis, and cervical dysplasia. If there is no history of Hep B , she should recevie the vaccine, as well as the pneumococcal vaccine and an annual flu shot. A platelet count and a CBC with differentials should be obtain at the first prenatal visit and repeated each trimester to edentify anemia, thrombocytopenia, leukopenia. The mouth is inspected for signs of infection such as thrush or hairy leukoplakia, the lungs are auscultated for signs of pneumonia, and the lymph nodes, liver, and spleen are palpated for signs of enlargement. Each trimester an eye exam should be done to detect complications of toxoplasmosis. She should also be checked routinely for changes indicating that HIV/AIDS is progressing. This would include the absolute CD4+ lymphocyte count. Weekly NST are started at 32 weeks.

When the CD4+ reaches a level of 200/mm3 or lower, what is more likely to develop?

oppoutunistic infections

When is a C-section reccommended for HIV-infected women?

When viral load as measured by HIV RNA is greater than 1000 copies/ml.

What is key to watch for in asymptomatic HIV postive pregnant woman?

Wt loss, thrush, pneumonia, and enlarged lymph nodes

What is the typical fetal active period?

last 40 minutes and peaks between 9:00 am and 1:00 pm in response to maternal hypoglycemia.

Advantages of Ultrasound (US)

it is noninvasive, painless, and nonradiating to both the woman and the fetus, and it has no known harmful effects to either.

What is US used for?

Soft tissue masses (such as tumors) can be differentiated, the fetus can be visualized, fetal growth can be followed, cervical length and impending cervical incompetence can be detected, and a number of other potential problems can be averted.

Types of ultrasound

Transabdominal and Transvaginal

What is nuchal translucency?

describes an area in the back of the fetal neck that is measured via US during the first trimester. Fetuses with a nuchal translucency of greater than 3 mm are at risk for certain birth defects, including trisomies 13,18, and 21

What is amniotic fluid index?

The ABD is divided into quadrants and the vertical diameter of the largest amniotic fluid pocket in each quadrant is measured. Women with and AFI of more than 20 cm are considered to have hydramnios, women with less than 5 cm at term are considered to have oligohydramnios. An AFi between 5-20 is normal.

What is the procedure for a NST?

An electronic fetal monitor is used to obtain a tracing of the FHR and fetal movement (FM). Two belts are used. One belt holds a device that detects uterine or fetal movement; the other belts holds a device that detects the FHR.

How are the results of a NST interpreted?

*Reactive test-shows at least 2 accelerations of FHR with FM of 15 beats/min, lasting 15 seconds or more, over 20 minutes. This is the desired result.

*Nonreactive test-the reactive criteria are not met.

*Unsatisfactory test- the data cannot be interpreted or there was inadequate FM.

What if the desired results are not acheived in NST?

Rescheduled when the fetus is most active or after the mother has eaten. 80% - 90% of nonreactive NST are due to fetal sleep states.

evaluates the respiratory function (o2 and Co2 exchange) of the placenta. It allows the healthcare team to identify the fetus at risk for intrauterine asphysxia by observing the response of the FHR to the stress of uterine contractions.

A fetal monitor is used to provide data. After a 15 min baseline recording of uterine activity and FHR, the tracing is evaluated for evidence of spontaneous contractions. If 3 spontaneous contractions of good quality and lasting 40-60 seconds occur in a 10 min window, the results are evaluated, and the test concluded. If no contractions occur or if insufficent contractions occur, contractions are induced.

Interpretation of CST results

*Negitive- shows 3 quality contractions without evidence of late decelerations. This is the desired result. It implies the fetus can handle the hypoxic stress of uterine ctx.

*Positve-shows persistent late decelerations with more than 50% of the contractions. The hypoxic stress of uterine ctx causes a slowing of the FHR. The pattern will not improve and will most likely get worse with additional ctx.

*Equivocal or suspicious- has nonpersistent late decelerations or decelerations associated with hyperstimulation (contraction frequency of every 2 min of duration of > 90 sec). When this test result occurs, more info is needed.

What test determines fetal lung development?

The lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol (PG). A 2:1 ratio of L/S and the presence of PG indicates the risk of RDS is very low.

involves obtaining a small sample of chorionic villi from the placenta.

Advantages and disadvantages of CVS

Advantages include early detection of certain fetal d/o with a decreased waiting time for results. Disadvantages include an increased risk to the fetus, inability to detect neural tube defects (NTD), and the potential for repeated invasive procedures.

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